The present invention relates to a central locking system for a motor vehicle having a means for locking and unlocking a door lock at each of a plurality of doors. A driving operation indicator indicates when the vehicle is being driven, and controls the locking and unlocking means to lock all the door locks when driving operation is indicated.
A central locking system of this general type is shown in German Patent Application DE-AS No. 19 21 696, which can perform the following functions: central locking and unlocking of all the doors from the outside of the vehicle by a change-over switch when the lock cylinder is actuated by the vehicle key; a central locking and unlocking of all doors from the inside of the vehicle through a manually operable touch contact locking switch; and a central locking of all the doors by actuating a driving-operation locking switch when the handbrake is released. In addition, in this system, when the handbrake is pulled, the doors are unlocked by actuating an inside door securing button separately and manually. On the other hand, unlocking of the doors is prevented when an inside door actuating handle is actuated. These functions ensure that in addition to the normal key-operated central function, when the handbrake is released, the doors are locked automatically, so that no vehicle door can be opened during the drive. This also makes it necessary to pull the handbrake before the doors can be opened.
An objective of the present invention is to provide a central locking system so that in addition to the key-operated central function, when the vehicle is started, an automatic central locking takes place, while an entering and exiting of the vehicle remains possible during the running of the vehicle engine. After each entrance or exit of the vehicle, central locking will occur when the vehicle is running.
These and other objectives are attained by the present invention by providing a central locking system of the above described type with override means for overriding the control of the door locking means by the driving operation indicator, which in the preferred embodiment, indicates operation of the engine. Actuation of the override means causes the door locking means to unlock all the doors, even when the engine operation indicator indicates engine operation. Control of the door locking means is returned to the engine operation indicator when the actuation of the override means is ceased. A preferred embodiment provides plural override means to temporarily override the control of the door locking means by the engine operation indicator. In the preferred embodiment, one of the override means is actuated by a switch in the passenger compartment of the vehicle, while another override means is actuated by a door switch which is closed when an inside door handle of the vehicle opens one of the vehicle doors. This allows entry and exit of the vehicle through all the vehicle doors when the engine is running.
Further objects, features and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings, which show for purpose of illustration only, an embodiment constructed in accordance with the present invention.